A restaurant has 23 tables. Some of the tables seat 4 persons and the rest seat two persons. In all, 76 persons can be seated at once. How many tables of each kind are there?

15 tables with 4 seats and 8 tables with 2 seats.

Step-by-step explanation:

x = 4 seated tables

y = 2 seated tables

x + y = 23

4x + 2y = 76

Multiply first equation by -2 to cancel y's:

-2x - 2y = -46

4x + 2y = 76

2x = 30

x = 30 / 2

x = 15

And we said 23 tables so:

23 - 15 = 8

x = 15

y = 8

no not all of them.

step-by-step explanation:

some of them have a square base.

(0,-3) see attached graph

step-by-step explanation:

a. to solve the system, graph the two equations.

x = y+3 becomes y=x-3 has m=1/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move up 1 unit and 1 unit to the right. plot a point and connect.

y=-4x+3 has m =-4/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move down four units and to the right 1 unit. plot a point and connect.

the solution is the point (x,y) where the two lines intersect. by the graph below it is (0,-3).

b. to solve by substitution, substitute y = -4x-3 into x= y+3

x= (-4x-3) +3

x=-4x

5x=0

x=0

now substitute x = 0 back in to find y.

y= -4(0)-3

y=0-3

y=-3

solution is (0,-3)

c. use elimination by adding the equations together.

x-y=3

4x+y=-3

5x=0

x=0

then substitute into one equation to find y.

y=-4(0)-3

y=-3